from matplotlib import transforms
from matplotlib.offsetbox import (AnchoredOffsetbox, AuxTransformBox,
                                  DrawingArea, TextArea, VPacker)
from matplotlib.patches import (Rectangle, Ellipse, ArrowStyle,
                                FancyArrowPatch, PathPatch)
from matplotlib.text import TextPath

__all__ = ['AnchoredDrawingArea', 'AnchoredAuxTransformBox',
           'AnchoredEllipse', 'AnchoredSizeBar', 'AnchoredDirectionArrows']


class AnchoredDrawingArea(AnchoredOffsetbox):
    def __init__(self, width, height, xdescent, ydescent,
                 loc, pad=0.4, borderpad=0.5, prop=None, frameon=True,
                 **kwargs):
        """
        An anchored container with a fixed size and fillable DrawingArea.

        Artists added to the *drawing_area* will have their coordinates
        interpreted as pixels. Any transformations set on the artists will be
        overridden.

        Parameters
        ----------
        width, height : float
            width and height of the container, in pixels.

        xdescent, ydescent : float
            descent of the container in the x- and y- direction, in pixels.

        loc : int
            Location of this artist. Valid location codes are::

                'upper right'  : 1,
                'upper left'   : 2,
                'lower left'   : 3,
                'lower right'  : 4,
                'right'        : 5,
                'center left'  : 6,
                'center right' : 7,
                'lower center' : 8,
                'upper center' : 9,
                'center'       : 10

        pad : float, default: 0.4
            Padding around the child objects, in fraction of the font size.

        borderpad : float, default: 0.5
            Border padding, in fraction of the font size.

        prop : `matplotlib.font_manager.FontProperties`, optional
            Font property used as a reference for paddings.

        frameon : bool, default: True
            If True, draw a box around this artists.

        **kwargs
            Keyworded arguments to pass to
            :class:`matplotlib.offsetbox.AnchoredOffsetbox`.

        Attributes
        ----------
        drawing_area : `matplotlib.offsetbox.DrawingArea`
            A container for artists to display.

        Examples
        --------
        To display blue and red circles of different sizes in the upper right
        of an axes *ax*:

        >>> ada = AnchoredDrawingArea(20, 20, 0, 0,
        ...                           loc='upper right', frameon=False)
        >>> ada.drawing_area.add_artist(Circle((10, 10), 10, fc="b"))
        >>> ada.drawing_area.add_artist(Circle((30, 10), 5, fc="r"))
        >>> ax.add_artist(ada)
        """
        self.da = DrawingArea(width, height, xdescent, ydescent)
        self.drawing_area = self.da

        super().__init__(
            loc, pad=pad, borderpad=borderpad, child=self.da, prop=None,
            frameon=frameon, **kwargs
        )


class AnchoredAuxTransformBox(AnchoredOffsetbox):
    def __init__(self, transform, loc,
                 pad=0.4, borderpad=0.5, prop=None, frameon=True, **kwargs):
        """
        An anchored container with transformed coordinates.

        Artists added to the *drawing_area* are scaled according to the
        coordinates of the transformation used. The dimensions of this artist
        will scale to contain the artists added.

        Parameters
        ----------
        transform : `matplotlib.transforms.Transform`
            The transformation object for the coordinate system in use, i.e.,
            :attr:`matplotlib.axes.Axes.transData`.

        loc : int
            Location of this artist. Valid location codes are::

                'upper right'  : 1,
                'upper left'   : 2,
                'lower left'   : 3,
                'lower right'  : 4,
                'right'        : 5,
                'center left'  : 6,
                'center right' : 7,
                'lower center' : 8,
                'upper center' : 9,
                'center'       : 10

        pad : float, default: 0.4
            Padding around the child objects, in fraction of the font size.

        borderpad : float, default: 0.5
            Border padding, in fraction of the font size.

        prop : `matplotlib.font_manager.FontProperties`, optional
            Font property used as a reference for paddings.

        frameon : bool, default: True
            If True, draw a box around this artists.

        **kwargs
            Keyworded arguments to pass to
            :class:`matplotlib.offsetbox.AnchoredOffsetbox`.

        Attributes
        ----------
        drawing_area : `matplotlib.offsetbox.AuxTransformBox`
            A container for artists to display.

        Examples
        --------
        To display an ellipse in the upper left, with a width of 0.1 and
        height of 0.4 in data coordinates:

        >>> box = AnchoredAuxTransformBox(ax.transData, loc='upper left')
        >>> el = Ellipse((0, 0), width=0.1, height=0.4, angle=30)
        >>> box.drawing_area.add_artist(el)
        >>> ax.add_artist(box)
        """
        self.drawing_area = AuxTransformBox(transform)

        super().__init__(loc, pad=pad, borderpad=borderpad,
                         child=self.drawing_area, prop=prop, frameon=frameon,
                         **kwargs)


class AnchoredEllipse(AnchoredOffsetbox):
    def __init__(self, transform, width, height, angle, loc,
                 pad=0.1, borderpad=0.1, prop=None, frameon=True, **kwargs):
        """
        Draw an anchored ellipse of a given size.

        Parameters
        ----------
        transform : `matplotlib.transforms.Transform`
            The transformation object for the coordinate system in use, i.e.,
            :attr:`matplotlib.axes.Axes.transData`.

        width, height : float
            Width and height of the ellipse, given in coordinates of
            *transform*.

        angle : float
            Rotation of the ellipse, in degrees, anti-clockwise.

        loc : int
            Location of this size bar. Valid location codes are::

                'upper right'  : 1,
                'upper left'   : 2,
                'lower left'   : 3,
                'lower right'  : 4,
                'right'        : 5,
                'center left'  : 6,
                'center right' : 7,
                'lower center' : 8,
                'upper center' : 9,
                'center'       : 10

        pad : float, optional
            Padding around the ellipse, in fraction of the font size. Defaults
            to 0.1.

        borderpad : float, default: 0.1
            Border padding, in fraction of the font size.

        frameon : bool, default: True
            If True, draw a box around the ellipse.

        prop : `matplotlib.font_manager.FontProperties`, optional
            Font property used as a reference for paddings.

        **kwargs
            Keyworded arguments to pass to
            :class:`matplotlib.offsetbox.AnchoredOffsetbox`.

        Attributes
        ----------
        ellipse : `matplotlib.patches.Ellipse`
            Ellipse patch drawn.
        """
        self._box = AuxTransformBox(transform)
        self.ellipse = Ellipse((0, 0), width, height, angle)
        self._box.add_artist(self.ellipse)

        super().__init__(loc, pad=pad, borderpad=borderpad, child=self._box,
                         prop=prop, frameon=frameon, **kwargs)


class AnchoredSizeBar(AnchoredOffsetbox):
    def __init__(self, transform, size, label, loc,
                 pad=0.1, borderpad=0.1, sep=2,
                 frameon=True, size_vertical=0, color='black',
                 label_top=False, fontproperties=None, fill_bar=None,
                 **kwargs):
        """
        Draw a horizontal scale bar with a center-aligned label underneath.

        Parameters
        ----------
        transform : `matplotlib.transforms.Transform`
            The transformation object for the coordinate system in use, i.e.,
            :attr:`matplotlib.axes.Axes.transData`.

        size : float
            Horizontal length of the size bar, given in coordinates of
            *transform*.

        label : str
            Label to display.

        loc : int
            Location of this size bar. Valid location codes are::

                'upper right'  : 1,
                'upper left'   : 2,
                'lower left'   : 3,
                'lower right'  : 4,
                'right'        : 5,
                'center left'  : 6,
                'center right' : 7,
                'lower center' : 8,
                'upper center' : 9,
                'center'       : 10

        pad : float, default: 0.1
            Padding around the label and size bar, in fraction of the font
            size.

        borderpad : float, default: 0.1
            Border padding, in fraction of the font size.

        sep : float, default: 2
            Separation between the label and the size bar, in points.

        frameon : bool, default: True
            If True, draw a box around the horizontal bar and label.

        size_vertical : float, default: 0
            Vertical length of the size bar, given in coordinates of
            *transform*.

        color : str, default: 'black'
            Color for the size bar and label.

        label_top : bool, default: False
            If True, the label will be over the size bar.

        fontproperties : `matplotlib.font_manager.FontProperties`, optional
            Font properties for the label text.

        fill_bar : bool, optional
            If True and if size_vertical is nonzero, the size bar will
            be filled in with the color specified by the size bar.
            Defaults to True if *size_vertical* is greater than
            zero and False otherwise.

        **kwargs
            Keyworded arguments to pass to
            :class:`matplotlib.offsetbox.AnchoredOffsetbox`.

        Attributes
        ----------
        size_bar : `matplotlib.offsetbox.AuxTransformBox`
            Container for the size bar.

        txt_label : `matplotlib.offsetbox.TextArea`
            Container for the label of the size bar.

        Notes
        -----
        If *prop* is passed as a keyworded argument, but *fontproperties* is
        not, then *prop* is be assumed to be the intended *fontproperties*.
        Using both *prop* and *fontproperties* is not supported.

        Examples
        --------
        >>> import matplotlib.pyplot as plt
        >>> import numpy as np
        >>> from mpl_toolkits.axes_grid1.anchored_artists import (
        ...     AnchoredSizeBar)
        >>> fig, ax = plt.subplots()
        >>> ax.imshow(np.random.random((10, 10)))
        >>> bar = AnchoredSizeBar(ax.transData, 3, '3 data units', 4)
        >>> ax.add_artist(bar)
        >>> fig.show()

        Using all the optional parameters

        >>> import matplotlib.font_manager as fm
        >>> fontprops = fm.FontProperties(size=14, family='monospace')
        >>> bar = AnchoredSizeBar(ax.transData, 3, '3 units', 4, pad=0.5,
        ...                       sep=5, borderpad=0.5, frameon=False,
        ...                       size_vertical=0.5, color='white',
        ...                       fontproperties=fontprops)
        """
        if fill_bar is None:
            fill_bar = size_vertical > 0

        self.size_bar = AuxTransformBox(transform)
        self.size_bar.add_artist(Rectangle((0, 0), size, size_vertical,
                                           fill=fill_bar, facecolor=color,
                                           edgecolor=color))

        if fontproperties is None and 'prop' in kwargs:
            fontproperties = kwargs.pop('prop')

        if fontproperties is None:
            textprops = {'color': color}
        else:
            textprops = {'color': color, 'fontproperties': fontproperties}

        self.txt_label = TextArea(label, textprops=textprops)

        if label_top:
            _box_children = [self.txt_label, self.size_bar]
        else:
            _box_children = [self.size_bar, self.txt_label]

        self._box = VPacker(children=_box_children,
                            align="center",
                            pad=0, sep=sep)

        super().__init__(loc, pad=pad, borderpad=borderpad, child=self._box,
                         prop=fontproperties, frameon=frameon, **kwargs)


class AnchoredDirectionArrows(AnchoredOffsetbox):
    def __init__(self, transform, label_x, label_y, length=0.15,
                 fontsize=0.08, loc=2, angle=0, aspect_ratio=1, pad=0.4,
                 borderpad=0.4, frameon=False, color='w', alpha=1,
                 sep_x=0.01, sep_y=0, fontproperties=None, back_length=0.15,
                 head_width=10, head_length=15, tail_width=2,
                 text_props=None, arrow_props=None,
                 **kwargs):
        """
        Draw two perpendicular arrows to indicate directions.

        Parameters
        ----------
        transform : `matplotlib.transforms.Transform`
            The transformation object for the coordinate system in use, i.e.,
            :attr:`matplotlib.axes.Axes.transAxes`.

        label_x, label_y : str
            Label text for the x and y arrows

        length : float, default: 0.15
            Length of the arrow, given in coordinates of *transform*.

        fontsize : float, default: 0.08
            Size of label strings, given in coordinates of *transform*.

        loc : int, default: 2
            Location of the direction arrows. Valid location codes are::

                'upper right'  : 1,
                'upper left'   : 2,
                'lower left'   : 3,
                'lower right'  : 4,
                'right'        : 5,
                'center left'  : 6,
                'center right' : 7,
                'lower center' : 8,
                'upper center' : 9,
                'center'       : 10

        angle : float, default: 0
            The angle of the arrows in degrees.

        aspect_ratio : float, default: 1
            The ratio of the length of arrow_x and arrow_y.
            Negative numbers can be used to change the direction.

        pad : float, default: 0.4
            Padding around the labels and arrows, in fraction of the font size.

        borderpad : float, default: 0.4
            Border padding, in fraction of the font size.

        frameon : bool, default: False
            If True, draw a box around the arrows and labels.

        color : str, default: 'white'
            Color for the arrows and labels.

        alpha : float, default: 1
            Alpha values of the arrows and labels

        sep_x, sep_y : float, default: 0.01 and 0 respectively
            Separation between the arrows and labels in coordinates of
            *transform*.

        fontproperties : `matplotlib.font_manager.FontProperties`, optional
            Font properties for the label text.

        back_length : float, default: 0.15
            Fraction of the arrow behind the arrow crossing.

        head_width : float, default: 10
            Width of arrow head, sent to ArrowStyle.

        head_length : float, default: 15
            Length of arrow head, sent to ArrowStyle.

        tail_width : float, default: 2
            Width of arrow tail, sent to ArrowStyle.

        text_props, arrow_props : dict
            Properties of the text and arrows, passed to
            `.textpath.TextPath` and `.patches.FancyArrowPatch`.

        **kwargs
            Keyworded arguments to pass to
            :class:`matplotlib.offsetbox.AnchoredOffsetbox`.

        Attributes
        ----------
        arrow_x, arrow_y : `matplotlib.patches.FancyArrowPatch`
            Arrow x and y

        text_path_x, text_path_y : `matplotlib.textpath.TextPath`
            Path for arrow labels

        p_x, p_y : `matplotlib.patches.PathPatch`
            Patch for arrow labels

        box : `matplotlib.offsetbox.AuxTransformBox`
            Container for the arrows and labels.

        Notes
        -----
        If *prop* is passed as a keyword argument, but *fontproperties* is
        not, then *prop* is be assumed to be the intended *fontproperties*.
        Using both *prop* and *fontproperties* is not supported.

        Examples
        --------
        >>> import matplotlib.pyplot as plt
        >>> import numpy as np
        >>> from mpl_toolkits.axes_grid1.anchored_artists import (
        ...     AnchoredDirectionArrows)
        >>> fig, ax = plt.subplots()
        >>> ax.imshow(np.random.random((10, 10)))
        >>> arrows = AnchoredDirectionArrows(ax.transAxes, '111', '110')
        >>> ax.add_artist(arrows)
        >>> fig.show()

        Using several of the optional parameters, creating downward pointing
        arrow and high contrast text labels.

        >>> import matplotlib.font_manager as fm
        >>> fontprops = fm.FontProperties(family='monospace')
        >>> arrows = AnchoredDirectionArrows(ax.transAxes, 'East', 'South',
        ...                                  loc='lower left', color='k',
        ...                                  aspect_ratio=-1, sep_x=0.02,
        ...                                  sep_y=-0.01,
        ...                                  text_props={'ec':'w', 'fc':'k'},
        ...                                  fontproperties=fontprops)
        """
        if arrow_props is None:
            arrow_props = {}

        if text_props is None:
            text_props = {}

        arrowstyle = ArrowStyle("Simple",
                                head_width=head_width,
                                head_length=head_length,
                                tail_width=tail_width)

        if fontproperties is None and 'prop' in kwargs:
            fontproperties = kwargs.pop('prop')

        if 'color' not in arrow_props:
            arrow_props['color'] = color

        if 'alpha' not in arrow_props:
            arrow_props['alpha'] = alpha

        if 'color' not in text_props:
            text_props['color'] = color

        if 'alpha' not in text_props:
            text_props['alpha'] = alpha

        t_start = transform
        t_end = t_start + transforms.Affine2D().rotate_deg(angle)

        self.box = AuxTransformBox(t_end)

        length_x = length
        length_y = length*aspect_ratio

        self.arrow_x = FancyArrowPatch(
                (0, back_length*length_y),
                (length_x, back_length*length_y),
                arrowstyle=arrowstyle,
                shrinkA=0.0,
                shrinkB=0.0,
                **arrow_props)

        self.arrow_y = FancyArrowPatch(
                (back_length*length_x, 0),
                (back_length*length_x, length_y),
                arrowstyle=arrowstyle,
                shrinkA=0.0,
                shrinkB=0.0,
                **arrow_props)

        self.box.add_artist(self.arrow_x)
        self.box.add_artist(self.arrow_y)

        text_path_x = TextPath((
            length_x+sep_x, back_length*length_y+sep_y), label_x,
            size=fontsize, prop=fontproperties)
        self.p_x = PathPatch(text_path_x, transform=t_start, **text_props)
        self.box.add_artist(self.p_x)

        text_path_y = TextPath((
            length_x*back_length+sep_x, length_y*(1-back_length)+sep_y),
            label_y, size=fontsize, prop=fontproperties)
        self.p_y = PathPatch(text_path_y, **text_props)
        self.box.add_artist(self.p_y)

        super().__init__(loc, pad=pad, borderpad=borderpad, child=self.box,
                         frameon=frameon, **kwargs)
